Combined with the mitochondrial DNA, which identified the maternal line as Neanderthal, the full genomic picture told a specific story: the individual’s mother was Neanderthal, the individual’s father was Denisovan. The researchers tested multiple models of ancestry and found that the first-generation hybrid scenario—in which each parent came from a distinct hominin group—fit the data substantially better than alternatives that would produce the same overall proportion through multiple generations of mixed ancestry.
This was not an individual with some ancient Neanderthal or Denisovan ancestry diluted across generations. This was an individual whose mother, in the fullest biological sense, was Neanderthal, and whose father, in the fullest biological sense, was Denisovan.
Viviane Slon expressed the significance clearly: “We knew from previous studies that Neandertals and Denisovans must have occasionally had children together. But this is the first time that we have found a direct, first-generation offspring.”
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## Reading the Father’s History
The nuclear genome told a more complex story than the simple Neanderthal/Denisovan split. It also contained information about the more distant ancestry of each parent—particularly the father.
When researchers analyzed the Denisovan portion of the Denisova 11 genome—the chromosomes inherited from the father—they found something that was not purely Denisovan. The father’s genome contained a small but detectable fraction of Neanderthal ancestry. The statistical analysis placed this admixture event at approximately 300 to 600 generations before Denisova 11’s lifetime.
Three hundred generations, at a rough generational interval of 25 to 30 years, represents roughly 7,500 to 18,000 years. The Neanderthal ancestry in the father’s genome was old—not from a parent or grandparent or even a great-great-grandparent, but from an ancestor who lived many thousands of years before the encounter that produced Denisova 11 herself.